They lost the first leg at the Maksimir 1-0, so unless something remarkable happens in Amsterdam on Thursday, Dinamo will be in exactly the same position they were last season when Ivankovic was appointed. And when investment from Milan Bandic, the mayor of Zagreb, has made the league all but a walkover, Europe becomes the only measure of success.

Mamic could simply have denied the rumours about Scala. He could simply have said that Ivankovic's position is safe and that this season's European failure is down to an unfortunate draw. Initially, that is what he did, albeit in his characteristically aggressive way, attacking the newspaper that had printed the story. He then listed Ivankovic's successes, before lapsing into a foul-mouthed rant against journalists, the media in general, and finally YouTube, ending with the words "I'm going to stick YouTube on my dick".

By Mamic's standards, this latest indiscretion is small beer. His rise has been both remarkable and remarkably turbulent. Born in Bjelovar near Zagreb in 1959, he was initially a youth player at Dinamo and then, when it turned out he wasn't good enough, a fan. When he was 15, he started in business, selling Styrofoam cushions outside the Maksimir. His great leap forwards, though, came amid the gangster capitalism of the war years as he made lucrative investments in a forestry company and a drinks manufacturer, before selling his shares to an arms dealer.

He has since become an agent, and worked on the transfers that took Bosko Balaban to Aston Villa, Eduardo da Silva to Arsenal and Vedran Corluka to Manchester City. He claims that he and his brother Zoran, who is sporting director at the club, have a combined fortune of around £30m.

His career has been swaddled in controversy. He has admitted match-fixing on numerous occasions, was censured by Uefa last season after celebrating Dinamo's victory over the Lithuanian side Ekranes in the second qualifying round of the Champions League with a Nazi salute, and created a stir earlier this year for an inappropriate advance to a belly-dancer in Azerbaijan.

He was suspended from football for life 15 years ago after assaulting a director of the Croatian FA; the ban was swiftly forgotten, and the physical violence has continued. After missing out on the position of sports director, Mamic attacked the former Dinamo director Josip Soic, who only escaped by scaling a fence. He struck the NK Zagreb player Niko Ceka in 1995, and that same year almost knocked down a traffic policeman as the authorities attempted to tow away his illegally parked Jaguar. It took nine years for that case to come to court, by which time the policeman in question had conveniently forgotten the exact details of the incident.

In 2003, on crutches after a knee operation, he went to a meeting at the office of Vlasta Pavic, the then-mayor of Zagreb, and was told by Miljenko Mesic, the director of the city planning authority, that his plans for a city-centre skyscraper had been rejected. He set about Mesic with his crutches, and received in return a blow to the head so hard it broke a bone in Mesic's hand. Mysteriously, no charges were pressed, and planning permission was later granted.

Mamic's favourite target, though, has been the press. The journalist Kristijan Toplaja was forced to flee and hide in some nearby bushes as Mamic took exception to his line of questioning. He hit a journalist from 24 Sata with a salt-cellar, and issued death treats to journalists from Jutarnji List.

So why the recent rant against YouTube? The problem with citizen journalism is that citizens tend to say what they think, and much of what has been posted on YouTube about Mamic has not been positive. There have been countless clips of fans calling for his resignation (the presidency, held by Mirko Barisic, is largely an honorific role), some simply abusive, others listing in some details his supposed crimes.

For all Dinamo's recent success, Mamic is widely distrusted. The Bad Blue Boys, the hard-core of the Dinamo fans, have made clear that they feel his frequent outbursts are beginning to undermine the club, and questions are being asked about just how much of the money recouped in transfer fees is being reinvested. In the summer, the Croatian public ombudsman Jurica Malcic sent a letter to the minister of science, education and sport, Dragan Primorac, asking whether Mamic's position as both an agent and the vice-president of what is, after all, a body still in part publicly funded didn't represent a conflict of interest.

No action has, as yet, been taken, and Mamic has come through worse crises before, but you do wonder how hostile the atmosphere around Dinamo could become if they are, as expected, knocked out of the Uefa Cup on Thursday.